Feed mechanism



FEED MECHANISM Filed July 1921 CHARLES F.

5 is reciprocable.

Patented May 20, 1930 earner serie OSGOOD, OF CLABEMONT, NEVJ" HAIVIESEIBE, ASSIGNOR T9 SULLIVAN MACHINERY COMPANY, A CORPORATION OF MASSACHUSETTS FEED MECHANISM Application filed July 1,1821. Serial No. 481,977.

My invention relates to feeding mechanisms and more especially to feeding mechanisms for use in connection with rock drilling devices. 1

An object of my invention is to provide an improved feeding mechanism. Another objectpf my invention is to provide an improved feeding mechanism for rock drilling devicestogether with an improved control means therefor. A further. object of my invention is to provide improved feeding mechanism having main control means and auxiiiary control means operative to instantaneously control the action of the feeding incohanism without adjustment of the main control means. Other objects and advantages of my invention will appear in the course of the followingspecification and appended claims.

In the accompanying drawings I have shown for purposes of illustration one form which my invention may assume in practice.

In these drawings,-

Fig. 1 is a central longitudinal section with parts broken away through the rear end of a motor cylinder and through the feeding mechanism therefor.

Fig. 2 is a transverse section on a line corresponding to the oroken line 22 of- Fig. 1.

Fig. 3 is check valve.

In the illustrative embodiment of my invention, I have shown the same employed in eifecting feeding movement of a fluid pressure motor 1 which may be of any well-known form and accordingly requires no further description. The feeding mechanism proper comprises a cylinder 2 having a bore 3 in which a piston 4 provided with a piston rod In the normal mode of operation of the feeding mechanism, however, the piston 4, whose rod 5 is provided with a point 6 adapted to rest against a suitable an enlarged detail view of the abutment, remains stationary and the cylinder 2 moves relatively thereto and so effects feeding movement of the motor 1. For the purpose of controlling the operation of the feeding mechanism and also of the motor 1, I provide a control valve generally designated 7 which comprises a ported bushing 8' and concentrically disposed therein a tapered hollow valve 9 to whose interior 1O fluid under pressure is supplied by way of connection 11. Motive fluid is supplied to the hammering motor 1 under the control of valve 9 in a well known manner. An illustration of the required ports and passages for this purpose may be found in the patent to Gil The valve 9 Said chamber communicates by way of a further passage 16 with the front end of the cylinder 2. It will be obvious. that, when air is supplied to the passage 14, 16, by the placing in communication the groove 12 with the port 13, relative movement between the cylinder 2 and piston 4 will take place and that if the point 6 is supported upon an abutment, the drill 1 will be fed toward the work. It will also be obvious that if it be desired to continue the operation of the drill while reducing the feed this may not be accomplished with the structure so far described and for this purpose I have provided further controlling mechanism generally indicated by 20. This mechanism comprises a valve 21 having an extended cylindrical portion22 reciprocable in the chamber 15 and adapted when moved to theextreme left hand limit of its travel in Fig. 2 to interrupt communication between the passages14, and 16. The valve likewise comprises a pair of pistons 23 andv24 separated by an annular groove 25 and these pistons are adapted to-cooperate with a passage 26 communicating with the end of the cylinder and'a passage 27 communicating' through a spring loaded ball check valve 28, with the'atmosphere. stem 29 provided with a push button 30 cooperates tomaintain the valve 21 normally while causing the piston 23 to interrupt c0mmunication between the passages 26' and 27, this being accomplished by a spring 31. When, however, the push button 80 is pressed the valve 21 will be moved to the left in Fig. 2, the communication between passages 14 and 16, and so between the air supply line 11 and the forward end of the feed cylinder 2, will be interrupted while, depending upon the distance that the valve 21 is moved to the left, a. greater or less exhaust will be permitted through the passage 26, groove 25, passage 27 and spring loaded check valve 2-8. It will be clear that by varying the spring pressure upon the check valve 28, it will be readily possible to control the minimum strength of fed and so that the eflcots of operation of the valve 21 may be more or less varied irrespective of its degree of movement. The purpose of the minimum strength of feed is to support the weight of the drilling mechanism at its operating position when the auxiliary valve is actuated which will prevent the drill actuating mechanism from falling away from the drill steel in case it is abnormally held in suspended position. A spring 32 and ported adjustable follower 33 are provided for the purpose of permitting the adjustment of the pressure upon the valve 28. It will be understood that the cylinder 2 is provided With the usual vent hole 34 so that air may escape from below the piston 4.

The mode of operation of this mechanism will be readily apparent. Assume that the drill is operating at full speed and that it is desired to interrupt the feed momentarily and reduce the force thereof without changing the rate of operation of the motor 1. The push button 30 will then be depressed more or as may be desired until the force of feed has been slacli'ened as much as may be wished. By forcing the push button 30 to the left hand limit of its possible movement, the feed can be arrested almost instantaneously and by alternately opening it wide and allowing it to close, the strength of said feed may be adjusted within fairly wide limits depending upon the duration of the periods when it is opened and closed. It will be noted that the vent passages are larger than the supply passages wherefore this effect may be more readily accomplished.

While I have in this application specifically described and shown one form which my invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in other forms without departing fro-m its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is 1. In a rock drilling mechanism, the combination witha drilling motor, pressure fluid actuated feeding means therefor, and a pres sure fluid supply for said motor and feeding means, of controlling means for said feeding means including a manually operable valve controlling the exhaust of pressure fluid from said feeding means, and a cooperating pressure fluid controlled valve automatically controlling said exhaust.

2. In a rock drilling mechanism, the combination with a drilling motor, pressure fluid actuated feeding means therefor, and a pressure fluid supply for said motor and feeding means, of feed controlling means including an exhaust port, a manually operable auxiliary valve controlling fluid flow through said exhaust port, and cooperating means for automatically preventing the exhaust of pressure fluid from said feeding means through said exhaust port below a predetermined point.

3. In a rock drilling mechanism, the combination with a drilling motor, pressure fluid actuated feeding means therefor, and a pressure fluid supply for said motor and feeding means, of a passage leading from said throttle valve to said feeding means and a passage leading from said feeding means to atmos phere, a manually operable reciprocable valve operable substantially instantaneously at the will of the operator for sequentially controlling said passages and a cooperating autoy matic pressure controlled valve set at a pre determined minimum feeding pressure for preventing said feeding pressure to be reduced below a predetermined minimum.

4:. In a feeding mechanism, a feed cylinder, a feed piston therein, and controlling means therefor comprising a valve controlling a connection between the source of the fluid pressure and said feeding mechanism, a second valve controlling the connection between said source and said feeding mechanism, a manually operable valve operative to permit ventingof said feeding mechanism to the atmosphere, and a cooperating spring loaded check valve automatically controlling the communication between said feeding means and the atmosphere when said last mentioned valve is in operation.

In testimony whereof I aflix my signature.

CHARLES F. OSGOOD. 

